环境雌激素双酚A对成年小鼠学习记忆和突触结构的影响*

双酚A (bisphenol, BPA)是一种广泛存在的环境内分泌干扰物,它可与雌激素受体结合干扰内源性雌激素对中枢神经系统的调控作用。本研究通过将10周龄小鼠灌胃染毒BPA (0.4、4、40 mg/kg/day)3个月,研究长期BPA暴露对成年小鼠记忆行为和突触可塑性的影响。开场行为测试结果表明, BPA (0.4、4、40 mg/kg/day)增加雄性的站立次数和理毛频率, BPA (4 mg/kg/day)却显著减少雌鼠的站立次数。水迷宫和被动回避行为模型检测显示, BPA主要损伤雄鼠的空间学习记忆和被动回避记忆。通过制备海马CA1区超薄切片后,电镜观测发现, BPA (0.4、40 mg/kg/day)暴露降低雄鼠海马CA1区突触数密度,缩短雄鼠突触前活性带长度,减小雄鼠突触后致密体(PSD)厚度,增加雄鼠突触间隙宽度。进一步用Western blot方法检测突触前、后的标志性蛋白Synapsin I和PSD95以及兴奋性氨基酸NMDA受体NR1亚基和AMPA受体GluR1亚基蛋白的表达,发现BPA暴露致雄鼠Synapsin I、PSD95、NR1蛋白表达水平下调。而BPA对雌鼠的记忆行为、突触形态、突触蛋白和受体蛋白均没有明显作用。以上结果提示长期B PA暴露性别特异性地影响成年小鼠的活动性和探究行为,损伤雄鼠的学习记忆,这些作用可能通过下调突触蛋白和NMDA受体的表达而负性影响突触结构可塑性,最终影响雄鼠的学习记忆功能。     

Electrical conductivity of Nd and Ce co-doped Gd2Zr2O7 ceramics

In this study, (Gd_{1? x} Nd _x )₂(Zr_{1? x} Ce _x )₂O₇ (0 ≤ x ≤ 0.5) ceramics have been prepared by pressureless sintering at 1973 K to investigate the influence of Nd and Ce co-doping on their electrical conductivity. The electrical conductivity of the ceramics was investigated by impedance spectroscopy measurements from 723 to 1173 K over the frequency range of 20 Hz to 2 MHz in air. The measured values obey the Arrhenius relation. For each composition, the grain conductivity gradually increases with increasing temperature from 723 to 1173 K. At a given temperature, it gradually decreases with increasing neodymium and cerium contents from x = 0 to 0.3; thereafter, the grain conductivity exhibits a slight increase with further increasing neodymium and cerium contents up to x = 0.5.     

Demonstration and interpretation of ‘scutoid’ cells formed in a quasi-2D soap froth

ABSTRACT

Recently a novel type of epithelial cell has been discovered and dubbed the ‘scutoid’. It is induced by curvature of the bounding surfaces. We show by simulations and experiments that such cells are to be found in a dry foam subjected to this boundary condition.     

Stability of nanocrystalline disordered NiAl synthesized by mechanical alloying

The thermal stability of highly disordered mechanically alloyed nanocrystalline NiAl has been evaluated. The reordering of disordered NiAl(Cr) shows extremely fast kinetics on isothermal annealing at and above 673K, while the process is quite sluggish below this temperature. On the other hand, significant reordering in NiAl(Fe) takes place even at 573K. A unique dependence of reordering on the grain growth of the nanophase is evident during thermal treatment. Rapid grain coarsening begins only as the absolute temperature approaches approximately 0.4 T m, where T m is the melting point of the aluminide.     

How people think “if only …” about reasons for actions

When people think about how a situation might have turned out differently, they tend to imagine counterfactual alternatives to their actions. We report the results of three experiments which show that people imagine alternatives to actions differently when they know about a reason for the action. The first experiment (n = 36) compared reason – action sequences to cause – effect sequences. It showed that people do not imagine alternatives to reasons in the way they imagine alternatives to causes: they imagine an alternative to an action more than an effect, and to a cause more than a reason. The second experiment (n = 214) and the third experiment (n = 190) both show that different sorts of reasons have different sorts of effects on how people imagine alternatives to actions. People imagine an alternative to an action (the protagonist went to a ball) less often when they know the reason for the action was an obligation (he had to participate in fundraising) compared to when they know about a weaker reason (he wanted to meet a famous violinist) or no reason. The second experiment shows the effect for a social obligation and the third experiment replicates and extends it to a health obligation. We interpret the results in terms of the possibilities that people keep in mind about actions and their reasons.     

Exploring the determinants of dual goal facilitation in a rule discovery task

Wason's standard 2-4-6 task requires discovery of a single rule and leads to around 20% solutions, whereas the dual goal (DG) version requires discovery of two rules and elevates solutions to over 60%. We report an experiment that aimed to discriminate between competing accounts of DG facilitation by manipulating the degree of complementarity between the to-be-discovered rules. Results indicated that perfect rule complementarity is not essential for task success, thereby undermining a key tenet of the goal complementarity account of DG facilitation. The triple heterogeneity account received a good degree of support since more varied triple exploration was associated with facilitatory DG conditions, in line with this account's prediction that task success is associated with the creative search of the problem space. The contrast class account (an extension of Oaksford & Chater's, 1994, iterative counterfactual model) was also corroborated in that the generation of descending triples was demonstrated to be the dominant predictor of DG success. We focus our discussion on conceptual ideas relating to the way in which iterative counterfactual testing and contrast class identification may work together to provide a powerful basis for effective hypothesis testing.     

Comparison of the MMPI and MMPI-2 Among Job Applicants

The primary objective was to compare the MMPI-2 profiles for professional job applicants with corresponding profiles on the original MMPI. Male and female MMPI-2 profiles were also compared, and correlational and factor analyses were used to examine: A) Interscale correlations vis-à-vis item overlap, and B) The impact of K-corrections. The subjects were 82 auditor applicants, plus 212 sales and management applicants from an earlier study. The original MMPI was found to overpathologize applicant profiles. Male and female MMPI-2 profiles differed only on Mf. Scales L, K, and Hy formed a favorable cluster for job applicants, while F, Hs, Pt, Sc formed one unfavorable cluster—and D, Si a second. K-corrections consistently moved clinical scales in the direction of the favorable cluster.     

延迟满足情境中2岁儿童对行为的自我控制能力和延迟策略的使用

以2岁儿童为被试,探讨其在延迟满足情境中的自我控制能力发展的状况。结果表明:(1)2岁儿童已具有一定程度的自我控制能力,个体差异显著,性别差异不显著;(2)2岁儿童已能使用一定的延迟策略,包括问题解决、分心、寻求安慰、消极等待、寻求他人帮助、回避等,其中使用频率最高的是分心策略;(3)不同的策略对延迟时间有着不同的影响;(4)儿童对策略的使用不会因延迟满足情境的不同而出现显著差异。     

Presurgical MMPI-2 Cluster Profiles Predict 1-Year Low-Back Surgery Outcomes

The primary purpose of this study was to examine whether empirically derived cluster profiles based on scores from the Minnesota Multiphasic Personality Inventory-2 (MMPI-2) predicted outcomes of surgery at 1 year for patients with low-back pain. On the basis of hierarchical cluster analysis of presurgery MMPI-2 scores for 60 patients, three interpretable and significant subgroups were formed. These consisted of a pathological/neurotic type, a double V-code type, and a normal type. The patents in the normal type were significantly more likely to report beneficial outcomes of surgery in terms of disability and pain than those in the other 2 types. These findings extend previous research and suggest (1) low-back surgery candidates are heterogeneous in their psychological profiles, and (2) MMPI-2 profiles are predictive of low-back surgery outcome. Future research should focus on identifying physiological substrates for these distinct profiles and investigating the effectiveness of presurgical psychological interventions based on profile type.     

效果量的意义及测定方法

文介绍了效果量在心理学研究中的意义以及评价效果量大小的标准,特别是说明了d,rpb^2,η^2和ω^2几个效果量的测定方法,并提出了提高效果量的措施及对效果量作研究的评论。